Cleaning composition for post-etch or post ash residue removal from a semiconductor substrate and corresponding manufacturing process

ABSTRACT

A cleaning composition for post-etch or post ash residue removal from a substrate used in semiconductor industry and a corresponding use of said cleaning composition is described. Further described is a process for the manufacture of a semiconductor device from a semiconductor substrate, comprising the step of post-etch or post ash residue removal from a substrate by contacting the substrate with a cleaning composition according to the invention.

The present invention relates to a cleaning composition for post-etch orpost ash residue removal from a substrate used in semiconductor industryand to a corresponding use of said cleaning composition. The presentinvention further relates to a process for the manufacture of asemiconductor device from a semiconductor substrate, comprising the stepof post-etch or post ash residue removal from a substrate by contactingthe substrate with a cleaning composition according to the invention.

Processes for manufacturing semiconductor devices are multiple-stepsequences of photolithographic and chemical processing steps duringwhich electronic circuits are gradually created on a wafer made of puresemiconducting material (a “semiconductor wafer”). Preferably, siliconis used as the semiconductor material. A typical semiconductor wafer ismade out of extremely pure silicon that is grown into mono-crystallinecylindrical ingots (boules) up to 300 mm in diameter using the so-called“Czochralski process”. These ingots are then sliced into wafers about0.75 mm thick and polished to obtain a very regular and flat surface.The particular process for manufacturing semiconductor wafers isstructured in several phases, comprising e.g. the so-called“front-end-of-line” (“FEOL”) and “back-end-of-line” (“BEOL”) processingphases.

The FEOL processing phase refers to the formation of transistorsdirectly in the material (usually the silicon) of the semiconductorwafer. The raw semiconductor wafer is engineered by the growth of anultrapure, virtually defect-free silicon layer through epitaxy.Front-end surface engineering is followed by growth of the gatedielectric (usually silicon dioxide), patterning of the gate, patterningof the source and drain regions, and subsequent implantation ordiffusion of dopants into the semiconducting material to obtain thedesired complementary electrical properties.

Once the various devices (e.g. dynamic random access memories, DRAMs;static random access memories, SRAMs; electrically programmable readonly memories, EPROMs; or complementary metal on silicon, CMOS) havebeen created in FEOL processing, they must be interconnected to form thedesired electrical circuits. This occurs in a series of wafer processingsteps collectively referred to as BEOL. The BEOL processing phaseinvolves creating metal interconnecting wires on the semiconductorwafer's surface that are isolated by layers made of material with lowdielectric constant.

With the introduction of copper as electrically conductive material,replacing aluminium, sophisticated multiple-step manufacturing processesfor forming integrated circuit interconnects on semiconductor substrateshave been developed. A typical process in manufacturing thesemiconductor integrated circuit requires hundreds of steps. These stepsinclude several kinds of stages such as diffusion, lithography, etching,ion implantation, deposition and sputtering. In these kinds of stages,diffusion and implantation generally require longer processing time thanother process stages which may require less processing time. Inaddition, some processes, e.g., those with longer processing time, canbe simultaneously performed on several semiconductor wafer lots(commonly referred to as a “batch”). In a semiconductor wafer'sprocessing line, several lots (and/or batches) and many kinds ofproducts are put into the processing line continuously at the same time.Thus, many kinds of products are operated on during different kinds ofstages in the processing flow. But since the processing time of eachproduct is different from each other, determining how many and whichsemiconductor wafers to be dispatched into a stage of the processingflow is a logistic challenge. As another consideration, some processesmust be performed within a certain amount of time after other processes.For example, after a deposition step a semiconductor wafer can beexposed to air for only a limited amount of time before the quality ofthe deposited film will begin to degrade. The time between processes isoften referred to as the “queue time”. Limits on this time are oftenreferred to as “queue time constraints”.

One particular multiple-step manufacturing process for formingintegrated circuit interconnects on semiconductor substrates is known asdamascene process with its variants like the dual damascene process,including the TFVL (“trench-first-via-last”) dual damascene process, theVFTL (“via-first-trench-last”) dual damascene process, the self-aligneddual damascene process or the dual damascene patterning process withetch mask, e.g. with metal hard mask (for the latter see e.g. documentU.S. Pat. No. 6,696,222). In the damascene processing technology, thedesired integrated circuit interconnect structure is patterned byetching the shape of the structure into the underlying inter-layerdielectric (“ILD”) materials. After the patterning, typically a thinbarrier layer (e.g. made of Ta/TaN, TiN, CoWP, NiMoP, NiMoB) isdeposited on top of the etched structure, e.g. as copper diffusionbarrier. On top of that barrier layer a seed layer is often depositedwhich supports better adhesion of the copper on the underlying materialand acts as catalytic material during the plating process as well.Typical materials for these seed layers are compounds which include Pdor other compounds, e.g. of polymers and organic materials. The originaldeposition process (damascene process) was designed to process eachlayer on its own.

Hence, the so called “vertical interconnect accesses” (“Vias”), theelectrically conductive interconnects usually comprising or consistingof copper, and the overlying metallization levels have different processsteps and demand a sequence of cleaning, material deposition,chemical-mechanical polishing (“CMP”), and another cleaning step foreach layer. A copper technology using this sequence for itsmetallization levels as well as for its ILDs and inter via dielectrics(“IVD”s) is often called a “single damascene process”. Typically, in thesingle damascene process each level requires its own cap layer or etchstop layer, a separate ILD layer, and at the top there is a need for amaterial—for instance SiO₂— that can be polished together with theinterconnect metal copper. As an alternative to the single damasceneprocess, the “dual damascene” processing technology combines certainsimilar process steps to one single process step, thus reducing thenumber of process steps and the time and costs required to build theBEOL stack of different layers. Accordingly, the dual damascene processfabricates the IVD and the metallization layer at once.

Multiple-step manufacturing processes for forming integrated circuitinterconnects on semiconductor substrates like the damascenemanufacturing process or its variants thus usually comprise one or moreprocess steps which require an “opening” of the Vias, usually byapplying a dry etching technology like reactive ion etching (“RIE”) orplasma etching (also known as chemical dry etching), which involvereactive etching gases promoted with plasma energy.

Such Via-opening process steps usually comprise etching of one or moredifferent (consecutive) layers situated above the Vias, which layers maycomprise electrically conductive, electrically semi-conductive and/orinsulating materials. Examples of such different (consecutive) layersare photoresist layers, bottom anti-reflective coating (BARC) layers,etch mask layers (e.g. metal hard mask layers, preferably comprisingTiN, or polymer mask layers), ILD layers (e.g. comprising SiO₂ orsilicon oxynitride) or low k material layers. Etching of said differentlayers is usually performed selectively (often by applying one or moreetch mask layers to protect areas of a layer which should not be etchedin a particular etching step) over a part of their horizontal extensionsto create defined openings for accessing certain areas of one or moresubjacent layers, until a defined segment of the Via is reached at thebottom of the stack of layers.

Said etching processes produce residues from the interaction of thereactive plasma gases used in the etching process and the materials theyinteract with. The composition of said residues is influenced by thetype of etching applied, the material of the layer etched (e.g. theresist), any underlying substrates and the process conditions applied.If the etching residues are not removed from the substrate, they caninterfere with subsequent processes involving the substrate. Suchremoval of or cleaning from etching residues is often referred to as“post-etch residue” removal or as “post-ash residue” removal. The effectof poor removal or cleaning can result in low yield, low reliabilityand/or low performance of an affected semiconductor device. Types ofresidues that should be removed often comprise organic compounds likeorganic polymers which may or may not comprise fluorine, metal-organiccomplexes, e.g. complexes of Ti (like fluorine complexes of Ti, alsoreferred to as “TiF_(x)”, or oxygen complexes of Ti, also referred to as“TiO_(x)”) and/or Cu (like fluorine complexes of Cu, also referred to as“CuF_(x)”, or oxygen complexes of Cu, also referred to as “CuO_(x)”, orCu hydroxide compounds, also referred to as Cu(OH)_(x), in particularCu(OH)₂) and/or residues comprising metallic materials, e.g. Al, AlCu(i.e. an alloy of Al and Cu), HfO_(x) (i.e. hafnium oxide) Ta, TaN, Tiand/or TiN. Inappropriate cleaning can also lead to unsatisfactory shorttimes during which a semiconductor wafer's surface during processing canbe exposed to air without experiencing degradation of quality of thedeposited film, resulting in queue time constraints and thus in alimitation of process flexibility. As another example, poor removal ofcopper-containing residues like CuO_(x) compounds or Cu(OH)_(x)compounds can lead to impaired electrical contacts in the Vias.

In summary, cleaning compositions for post-etch or post ash residueremoval (“post ash residue removal” also abbreviated to “PARR” in thistext) should preferably remove, to the highest extent possible,undesired residues from (previous) processing steps in a multiple-stepmanufacturing process for forming integrated circuit interconnects onsemiconductor substrates, while at the same time not or only to theleast possible extent compromising or damaging desired materials whichare also present on the semiconductor substrate's surface, like certaindielectric materials, e.g. low k material, and/or metallic interconnectmaterials, in particular copper.

The ongoing development in manufacturing processes for formingintegrated circuit interconnects on semiconductor substrates (e.g.shrinking device dimensions, changes in etching conditions) and theongoing integration of new materials in said processes demandspecialized cleaning compositions to meet these changing requirements.The prior art also reflects this versatility of requirements and howthey have been addressed in the past.

For example, document WO 2004/100245 pertains to the removal ofpost-etch residues in semiconductor processing.

Document WO 2008/080097 describes a liquid cleaner for the removal ofpost-etch residues.

Document WO 2012/009639 pertains to an aqueous cleaner for the removalof post-etch residues.

Document US 2012/0009788 describes a cleaning solution, cleaning methodand damascene process using the same.

Document US 2012/0052686 pertains to a cleaning solution and damasceneprocess using the same.

Document WO 2014/197808 pertains to compositions and methods forselectively etching titanium nitride.

Document WO 2015/173730 describes a TiN pull-back and cleaningcomposition.

In view of the prior art there is still a need for a cleaningcomposition for post-etch or post ash residue removal from a substrateused in semiconductor industry which can satisfactorily remove residuesfrom one or more different layers (i.e. from layers which have beenetched before) selected from photoresist layers, bottom antireflectivecoating layers, etch mask layers, ILD layers and low k material layers,while at the same time not or to the least extent possible compromisingor damaging low k materials and/or metallic interconnect materials, inparticular copper, which are also present.

It was therefore a primary object of the present invention to provide animproved cleaning composition for post-etch or post ash residue removalfrom a substrate used in semiconductor industry for removing residuesfrom one or more different layers (which can be present on the substrateat the same time; i.e. from layers which have been etched before)selected from photoresist layers, bottom antireflective coating layers,etch mask layers, ILD layers and low k material layers, while at thesame time not or to the least extent possible compromising or damaginglow k materials and/or metallic interconnect materials, in particularcopper, which are also present on the substrate.

It was a more specific aspect of the primary object of the invention toprovide an improved process for the manufacture of a semiconductordevice from a semiconductor substrate, the process comprising a step ofpost-etch or post ash residue removal from a substrate, and inparticular further comprising a layer of copper and/or a low k material.

It has now been found that the primary object and other objects of theinvention are accomplished by a cleaning composition for post-etch orpost ash residue removal from a substrate used in semiconductorindustry, comprising (i.e. one or more further substances may bepresent) or consisting of (i.e. no further substances are present inaddition to component A to F as defined hereinafter):

-   -   (A) one or more etchants comprising fluoride, preferably        selected from the group consisting of ammonium fluoride,        ammonium bifluoride, triethanolammonium fluoride,        diglycolammonium fluoride, methyldiethanolammonium fluoride,        tetramethylammonium fluoride, triethylamine trihydrofluoride,        hydrogen fluoride, fluoroboric acid, tetrafluoroboric acid,        ammonium tetrafluoroborate, fluoroacetic acid, ammonium        fluoroacetate, trifluoroacetic acid, fluorosilicic acid,        ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate        and mixtures thereof    -   (B) one or more alkanolamines, preferably selected from the        group consisting of monoisopropanolamine, diisopropanolamine,        triisopropanolamine, 2-(2-aminoethylamino)-ethanol,        2-(2-aminoethoxy)-ethanol, 2-aminoethanol (CAS RN 141-43-5),        2-(N-methylamino) ethanol, 2-amino-1-propanol,        2-(2-hydroxyethylamino)ethanol (CAS RN 111-42-2),        2-[(2-aminoethyl)(2-hydroxyethyl)-amino]-ethanol,        tris-(2-hydroxyethyl)amine (CAS RN 102-71-6),        N-aminoethyl-N′-hydroxyethylethylenediamine,        N,N′-dihydroxyethyl-ethylenediamine,        2-[2-(2-aminoethoxy)ethylamino]ethanol,        2-[2-(2-aminoethylamino)-ethoxy]-ethanol,        2-[2-(2-aminoethoxy)-ethoxy]-ethanol,        tertiary-butyldiethanolamine, 3-amino-1-propanol,        isobutanolamine, 2-(2-aminoethoxy)-propanol and mixtures        thereof;    -   (C) one or more sulfonic acids, preferably selected from the        group consisting of methane sulfonic acid, ethanesulfonic acid,        propanesulfonic acid, butanesulfonic acid, hexanesulfonic acid,        3-(N-morpholino)propane sulfonic acid,        2-(N-morpholino)ethanesulfonic acid,        N-cyclohexyl-2-aminoethanesulfonic acid,        3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid,        N-cyclohexyl-3-aminopropanesulfonic acid and mixtures thereof;    -   (D) one or more corrosion inhibitors, preferably selected from        the group consisting of benzotriazole, 5-methyl-benzotriazole,        1,2,4-triazole, 5-aminotetrazole, 1-hydroxybenzotriazole,        5-amino-1,3,4-thiadiazol-2-thiol, 3-amino-1H-1,2,4 triazole,        3,5-diamino-1,2,4-triazole, tolyltriazole,        5-phenyl-benzotriazole, 5-nitro-benzotriazole,        3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,        2-(5-amino-pentyl)-benzotriazole, 1-amino-1,2,3-triazole,        1-amino-5-methyl-1,2,3-triazole, 3-mercapto-1,2,4-triazole,        3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole,        halobenzotriazoles where halo is selected from the group        consisting of fluorine, chlorine, bromine and iodine;        naphthotriazole, 1H-tetrazole-5-acetic acid,        2-mercaptobenzothiazole, 1-phenyl-2-tetrazoline-5-thione,        2-mercaptobenzimidazole, 4-methyl-2-phenylimidazole,        2-mercaptothiazoline, 2,4-diamino-6-methyl-1,3,5-triazine,        thiazole, imidazole, benzimidazole, triazine, methyltetrazole,        1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole,        1-phenyl-5-mercaptotetrazole, 2H-imidazole-2-thione,        4-methyl-4H-1,2,4-triazole-3-thiol,        5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl        phosphate, indazole, adenine, cytosine, guanine, thymine,        2,2′-azanediyldiacetic acid, propanethiol, ascorbic acid,        thiourea, ethylene urea, ethylene thiourea,        1,1,3,3-tetramethylurea, urea, uric acid, glycine,        dodecylphosphonic acid, oxalic acid, malonic acid, succinic        acid, nitrilotriacetic acid and mixtures thereof;    -   (E) citric acid, and    -   (F) water.

It was particularly surprising that the cleaning composition accordingto the invention was suited for removing from a substrate used insemiconductor industry residues from one or more different (consecutive)layers, preferably residues from all different (consecutive) layers,selected from the group consisting of photoresist layer, bottomanti-reflective coating layer, etch mask layer, ILD layer and low kmaterial layer, while at the same time not or to the least extentpossible compromising or damaging low k materials and/or metallicinterconnect materials, preferably copper, which are also present on thesubstrate.

It was also particularly surprising that the cleaning composition of theinvention as defined above allows

-   -   increased yields of functioning transistors or transistor        clusters on fully processed semiconductor wafers (comprising in        each case a layer of copper and a low k material): i.e. a yield        increase of about 1.9% in functioning transistors or transistor        clusters is observed on a series of semiconductor wafers after        their full processing which processing comprised a step of        post-etch and/or post ash residue removal from the surfaces of        said series of semiconductor wafers with a composition according        to the present invention at 45° C. for 60 s,    -   when compared with the respective yield observed on an        equivalent series of semiconductor wafers after their full        processing, which processing instead comprised a step of        post-etch and/or post ash residue removal from the surfaces of        the equivalent series of semiconductor wafers with an existing        composition from the prior art designed for a similar purpose of        removing post-etch or post ash residue from the surface of a        semiconductor substrate,        and/or    -   simplified manufacturing processes by reducing the number of        process steps, in particular the number of rinsing steps,        required for manufacturing a semiconductor device.

The invention as well as preferred embodiments and preferredcombinations of parameters, properties and elements thereof are definedin the appended claims. Preferred aspects, details, modifications andadvantages of the present invention are also defined and explained inthe following description and in the examples stated below.

In the context of the present invention, a “photoresist layer”means—consistent with the usual meaning in the technical field ofmicroelectronics or microlithography—a layer or film which, when exposedto light with a wavelength in the range of from 250 to 400 nm, theportion of the photoresist that was exposed to said light either becomes(i) soluble to a specific developer (“positive photoresist”) while theunexposed portion of the photoresist remains insoluble to thephotoresist developer, or the portion of the photoresist that wasexposed to said light becomes (ii) insoluble to a specific developer(“negative photoresist”) while the unexposed portion of the photoresistremains soluble to the photoresist developer. The term “photoresist” inthe context of the present invention comprises photopolymericphotoresists, photodecomposable photoresists and photocrosslinkingphotoresists.

In the context of the present invention, a “bottom anti-reflectivecoating” (“BARC”) or bottom resist anti-reflective coatingmeans—consistent with the usual meaning in the technical field ofmicroelectronics or microlithography—an organic or silico-organicpolymer used to improve the profile of a photoresist and the overallprocess operating window. BARCs are applied prior to the photoresist tohelp eliminate standing waves and the resulting defective/sloped resistsidewalls, which can commonly occur in imaged nanostructures due tovarying and reflected light intensities throughout the resist thickness.BARCS have to be selected based on the specific wavelength processesincluding i-Line, 248 nm, 193 nm (dry and immersion). They also have tobe compatible with the applied photoresist. BARCs are applied to asemiconductor substrate from organic polymer formulations using aspin-on process and are then heated (“baked”, “cured”) to a recommendedtemperature.

In the context of the present invention an “etch mask” means—consistentwith the usual meaning in the technical field of microelectronics ormicrolithography—a layer of a material that can withstand certainetching process steps undamaged and therefore serves as a protectinglayer for certain areas of subjacent material layers which should not beetched in a certain etching step. In the context of the presentinvention, an etch mask layer preferably comprises or consists of (a) ametallic material, preferably selected from the group consisting of Ti,TiN, La, LaN, HfO_(x) (i.e. hafnium oxide), Al, AlCu, or (b) an organicpolymeric material. An etch mask can also be a photoresist.

In the context of the present invention an “ILD” means—consistent withthe usual meaning in the technical field of microelectronics ormicrolithography—a dielectric material used to electrically separateclosely spaced interconnect lines arranged in several levels (multilevelmetallization) in an integrated circuit. An ILD usually has a dielectricconstant k≤3.9 to minimize capacitive coupling between adjacent metallines, e.g. Vias. In the context of the present invention, an ILDspreferably comprises or consists of SiO₂ and/or silicon oxynitride.

In the context of the present invention a “low k material”means—consistent with the usual meaning in the technical field ofmicroelectronics or microlithography—a material with a dielectricconstant κ<3.9 which is preferably selected from the group consisting of

-   -   silicon-containing materials, preferably selected from the group        consisting of SiO₂, silicon oxycarbide (SiOC),        tetraethylorthosilicate (TEOS), boron-doped phosphosilicate        glass (BPSG), fluorine-doped silicon dioxide (fluorosilicate        glass, FSG), carbon-doped silicon dioxide, organo silicate glass        (OSG), carbon-doped oxide (CDO), porous silicon dioxide, porous        carbon-doped silicon dioxide (e.g. known as Black Diamond™) II)        and spin-on silicon polymeric materials, preferably selected        from the group consisting of hydrogen silsesquioxane (HSQ) and        methylsilsesquioxane (MSQ); and    -   polymeric materials, preferably selected from the group        consisting of spin-on organic polymeric dielectrics, preferably        comprising polyimide (PI), polynorbornenes, benzocyclobutene and        polytetrafluorethylene (PTFE).

In the context of the present invention a “metallic interconnectmaterial” means—consistent with the usual meaning in the technical fieldof microelectronics or microlithography—a material selected from thegroup consisting of aluminium, cobalt, copper, ruthenium, titanium andtungsten. In the context of the present invention copper is preferred asa metallic interconnect material.

In the context of the present invention a “substrate used insemiconductor industry” or a “semiconductor substrate” preferablymean—consistent with the usual meaning in the technical field ofmicroelectronics or microlithography—a semiconductor wafer.

In the cleaning composition according to the invention as defined above,the one or more etchants comprising fluoride anions (A), the one or morealkanolamines (B), the one or more sulfonic acids (C) and the one ormore corrosion inhibitors (D) generally can in each case be used alone(as one single compound) or can be used in combination with othercompounds from the same type (etchant, alkanolamines, sulfonic acids orcorrosion inhibitor, respectively, as applicable).

In component (A) of the composition according to the invention, the oneor more etchants comprising fluoride can comprise one or more fluorideanions or provide one or more fluoride anions upon contact with water.

Preferred is therefore a cleaning composition according to the inventionas defined herein, wherein

-   -   the one or more etchants comprising fluoride (A) are selected        from the group consisting of ammonium fluoride, ammonium        bifluoride, triethanolammonium fluoride, diglycolammonium        fluoride, methyldiethanolammonium fluoride, tetramethylammonium        fluoride, triethylamine trihydrofluoride, hydrogen fluoride,        fluoroboric acid, tetrafluoroboric acid, ammonium        tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate,        trifluoroacetic acid, fluorosilicic acid, ammonium        fluorosilicate, tetrabutylammonium tetrafluoroborate and        mixtures thereof,    -   and preferably the or at least one etchant comprising        fluoride (A) is ammonium fluoride, and more preferably the        etchant (A) is ammonium fluoride,        and/or    -   the total amount of the one or more etchants comprising fluoride        (A), preferably ammonium fluoride, is in the range of from 0.001        to 1 wt.-%, preferably in the range of from 0.01 to 0.1 wt.-%,        based on the total weight of the cleaning composition.

A cleaning composition according to the invention which has such arelatively low content of one or more etchants comprising fluoride asdefined here above, preferably such a relatively low content of ammoniumfluoride (in particular where ammonium fluoride is the sole etchantpresent in the cleaning composition according to the invention) has theadvantages of better compatibility with low k materials (i.e. suchcleaning composition causes less damage to low k materials or low kmaterial layers than a similar cleaning composition with a highercontent of etchant, in particular of ammonium fluoride) and of producingless residual material, e.g. fluorine-containing etchants, which mayneed special treatment or deposit in order to dispose of it in anenvironmentally safe manner.

Also preferred is a cleaning composition according to the invention asdefined herein (or a cleaning composition according to the invention asdescribed above or below as being preferred), comprising or consistingof

-   (A) one or more etchants comprising fluoride, selected from the    group consisting of ammonium fluoride, ammonium bifluoride,    triethanolammonium fluoride, diglycolammonium fluoride,    methyldiethanolammonium fluoride, tetramethylammonium fluoride,    triethylamine trihydrofluoride, hydrogen fluoride, fluoroboric acid,    tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic    acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic    acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate    and mixtures thereof,    -   preferably in a total amount in the range of from 0.001 to 1        wt.-%, more preferably in the range of from 0.01 to 0.1 wt.-%,        based on the total weight of the cleaning composition;-   (B) one or more alkanolamines selected from the group consisting of    monoisopropanolamine, diisopropanolamine, triisopropanolamine,    2-(2-aminoethylamino)ethanol, 2-(2-aminoethoxy)-ethanol,    2-aminoethanol (CAS RN 141-43-5), 2-(N-methylamino) ethanol,    2-amino-1-propanol, 2-(2-hydroxyethylamino)ethanol (CAS RN    111-42-2), 2-[(2-aminoethyl)(2-hydroxyethyl)-amino]-ethanol,    tris-(2-hydroxyethyl)amine (CAS RN 102-71-6),    N-aminoethyl-N′-hydroxyethylethylenediamine,    N,N′-dihydroxyethyl-ethylenediamine,    2-[2-(2-aminoethoxy)ethylamino]ethanol,    2-[2-(2-aminoethylamino)-ethoxy]-ethanol,    2-[2-(2-aminoethoxy)-ethoxy]-ethanol, tertiary-butyldiethanolamine,    3-amino-1-propanol, isobutanolamine, 2-(2-aminoethoxy)-propanol and    mixtures thereof,    -   preferably in a total amount in the range of from 10 to 20        wt.-%, more preferably in the range of from 12 to 17 wt.-%,        based on the total weight of the cleaning composition;-   (C) one or more sulfonic acids selected from the group consisting of    methane sulfonic acid, ethanesulfonic acid, propanesulfonic acid,    butanesulfonic acid, hexanesulfonic acid), 3-(N-morpholino)propane    sulfonic acid, 2-(N-morpholino)ethanesulfonic acid,    N-cyclohexyl-2-aminoethanesulfonic acid,    3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid,    N-cyclohexyl-3-aminopropanesulfonic acid and mixtures thereof,    preferably in a total amount in the range of from 0.01 to 10 wt.-%,    more preferably of from 0.1 to 1 wt.-%, based on the total weight of    the cleaning composition;-   (D) one or more corrosion inhibitors selected from the group    consisting of benzotriazole, 5-methyl-benzotriazole, 1,2,4-triazole,    5-aminotetrazole, 1-hydroxybenzotriazole,    5-amino-1,3,4-thiadiazol-2-thiol, 3-amino-1H-1,2,4 triazole,    3,5-diamino-1,2,4-triazole, tolyltriazole, 5-phenyl-benzotriazole,    5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole,    1-amino-1,2,4-triazole, 2-(5-amino-pentyl)benzotriazole,    1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,    3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole,    5-phenylthiol-benzotriazole, halobenzotriazoles where halo is    selected from the group consisting of fluorine, chlorine, bromine    and iodine; naphthotriazole, 1H-tetrazole-5-acetic acid,    2-mercaptobenzothiazole, 1-phenyl-2-tetrazoline-5-thione,    2-mercaptobenzimidazole, 4-methyl-2-phenylimidazole,    2-mercaptothiazoline, 2,4-diamino-6-methyl-1,3,5-triazine, thiazole,    imidazole, benzimidazole, triazine, methyltetrazole,    1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole,    1-phenyl-5-mercaptotetrazole, 2H-imidazole-2-thione,    4-methyl-4H-1,2,4-triazole-3-thiol,    5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl    phosphate, indazole, adenine, cytosine, guanine, thymine,    2,2′-azanediyldiacetic acid, propanethiol, ascorbic acid, thiourea,    ethylene urea, ethylene thiourea, 1,1,3,3-tetramethylurea, urea,    uric acid, glycine, dodecylphosphonic acid, oxalic acid, malonic    acid, succinic acid, nitrilotriacetic acid and mixtures thereof,    -   preferably in a total amount in the range of from 0.001 to 10        wt.-%, more preferably of from 0.01 to 1 wt.-%, based on the        total weight of the cleaning composition;-   (E) citric acid,    -   preferably in a total amount in the range of from 0.1 to 25        wt.-%, more preferably in the range of from 5 to 25 wt.-%, even        more preferably in the range of from 10 to 25 wt.-% and yet even        more preferably in the range of from 15 to 25 wt.-%, based on        the total weight of the cleaning composition, and-   (F) water,    -   preferably as balance to a total of 100 wt.-% of the cleaning        composition.

The preferred amounts of components (A) to (F) are preferably present incombination with each other, i.e. preferably all components (A) to (F)are present in the respective preferred amount. This statement generallyapplies for preferred amounts indicated in the present text, mutatismutandis.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein

-   -   the or at least one alkanolamine (B) is        tris-(2-hydroxyethyl)-amine (also known as triethanolamine),        preferably the alkanolamine (B) is tris-(2-hydroxyethyl)amine,    -   and/or    -   the total amount of the one or more alkanolamines (B),        preferably tris-(2-hydroxyethyl)-amine, is in the range of from        10 to 20 wt.-%, preferably in the range of from 12 to 17 wt.-%,        based on the total weight of the cleaning composition.

It has been found that tris-(2-hydroxyethyl)-amine as alkanolamine (B)in the compositions of the present invention assists particularlyefficiently in removing organic polymer residues from a substrate usedin semiconductor industry.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein

-   -   the or at least one sulfonic acid (C) is methane sulfonic acid,        preferably the sulfonic acid (C) is methane sulfonic acid,    -   and/or    -   the total amount of the one or more sulfonic acids (C),        preferably methane sulfonic acid, is in the range of from 0.01        to 10 wt.-%, preferably of from 0.1 to 1 wt.-%, based on the        total weight of the cleaning composition.

A cleaning composition of the invention comprising the one or moresulfonic acids (C) as defined above, preferably methane sulfonic acid,more preferably in the total amounts as defined above, has the advantageof exerting its excellent post-etch or post ash residue cleaningperformance although comprising only a relatively low content of one ormore etchants, preferably of ammonium fluoride, as defined above, whencompared to known compositions of the prior art used for similartechnical applications, e.g. the composition of the present inventiononly requires about half the concentration (wt./wt.) or less of one ormore etchants, preferably of ammonium fluoride, when compared to knowncompositions of the prior art used for similar technical applications.Such a relatively lower concentration of one or more etchants,preferably of ammonium fluoride, of the composition according to thepresent invention further lowers the risk of damaging a low k materialwhich may also be present on a substrate used in semiconductor industry,as explained above. Specifically, such cleaning composition of thepresent invention exerts such excellent post-etch or post ash residuecleaning performance on a substrate used in semiconductor industry andat the same time does not or only to a very low extent compromise ordamage low k materials and/or metallic interconnect materials, inparticular copper, which are also present on the substrate.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein

-   -   the or at least one corrosion inhibitor (D) is glycine,        preferably the corrosion inhibitor (D) is glycine        and/or    -   the total amount of the one or more corrosion inhibitors (D),        preferably glycine, is in the range of from 0.001 to 10 wt.-%,        preferably of from 0.01 to 1 wt.-%, based on the total weight of        the cleaning composition.

A cleaning composition of the invention comprising the one or morecorrosion inhibitors (D) as defined above, preferably comprisingglycine, in particular in the total amounts as defined above, has theadvantage of decreasing lateral copper etching defects on a substrateused in semiconductor industry and thus minimizing so-called“smiling-curve” defects which can occur with certain etch processes, inparticular when compared with similar cleaning compositions which do notcomprise glycine.

Smiling curves are generally generated on a copper substrate when coppersurfaces are isotropically or anisotropically etched. One way how asmiling curve defect can be generated is e.g. when the middle of acopper structure is etched quicker than its sidewalls. This results in adepression of the etched structure in its middle, with the sidewallsremaining at e.g. their original height. The resulting etched structurethen resembles a smiling mouth. Another way how a smiling curve defectcan be generated is e.g. when a copper plug (as part of the surfacestructure of a semiconductor wafer) is etched somewhat in the middle,but quicker etch occurs at its sidewalls, thus undercutting thestructure. Depending on the extent of under-etching, the under-etchingwould either be classified as isotropic (i.e. high degree ofunder-etching) anisotropic (i.e. resulting in a circular etch shape), oran intermediate between isotropic and anisotropic etching phenomenons.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein the total amount ofcitric acid (E) is in the range of from 0.1 to 25 wt.-%, preferably inthe range of from 5 to 25 wt.-%, more preferably in the range of from 10to 25 wt.-% and yet more preferably in the range of from 15 to 25 wt.-%,based on the total weight of the cleaning composition.

It has surprisingly been found that a cleaning composition of theinvention which comprises citric acid, preferably in the total amountsas defined above, has several advantages over similar compositions whichdo not comprise citric acid or which do comprise other acids than citricacid, e.g. stronger acids (e.g. acids with a pKs value of 3.0 or below)like mineral acids. One such advantage is, that a cleaning compositionaccording to the invention comprising citric acid shows a particularlygood or particularly effective removal of copper oxide and/or copperhydroxide compounds (also referred to herein as CuO_(x) compounds orCu(OH)_(x) compounds, respectively). Insufficient removal of copperoxide and/or copper hydroxide compounds from the Vias can result inimpaired electrical contacts in the Vias and thus to reduced or impairedperformance of an affected semiconductor device. Another advantage isthat application of a cleaning composition according to the inventioncomprising citric acid results in cleaned semiconductor substrates whichcan be exposed to air for extended periods of time without developingcharacteristic defects (or only developing such characteristic effectsto a lesser extent when compared with similar cleaning compositionswhich do not comprise citric acid), e.g. associated with poor orinappropriate cleaning results, thus allowing extended queue times (e.g.extended by two times, preferably by five times and more preferably byup to ten times the queue times which are possible when using similarcompositions known from the prior art), which increases the overallflexibility of processes for manufacturing e.g. semiconductor wafers orproducts derived therefrom. Said characteristic defects compriseso-called “ball type” defects, i.e. the formation of ball likestructures comprising e.g. TiO_(x) and/or TiF_(x) compounds on theprocessed semiconductor substrate's surface, e.g. in the Vias, which canlead to impaired performance of a resulting semiconductor device.

Application of a cleaning composition according to the invention cantherefore help to favourably extend the queue time for certain steps ofprocessing a semiconductor substrate up to a possible queue time of morethan 20 hours, compared to less than 5 hours which can be accomplishedby application of similar compositions of the prior art which do notcomprise citric acid, in particular in the preferred total amounts asdefined above for cleaning compositions of the present invention. Yetanother such advantage is that a cleaning composition according to theinvention comprising citric acid comprises less residual material (e.g.strong and/or corrosive acids) which may need special treatment ordeposit in order to dispose of it in an environmentally safe manner,e.g. after its use in the process as described herein.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein components (A), (B),(C), (D) and (E) are used in the total amounts as defined above,preferably in the total amounts as defined above as being preferred, andwater (F) is used as balance to a total of 100 wt.-% of the cleaningcomposition in each case.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred wherein the above-definedtotal amounts, preferably the total amounts defined above as beingpreferred, of components (A), (B), (C), (D), (E) and (F) are combinedwith the preferred components (A), (B), (C), (D), (E) and (F), asdefined above.

Preferred is also a cleaning composition according to the invention asdefined herein (or a cleaning composition according to the invention asdescribed above or below as being preferred), comprising or consistingof

-   (A) one or more etchants comprising fluoride, selected from the    group consisting of ammonium fluoride, ammonium bifluoride,    triethanolammonium fluoride, diglycolammonium fluoride,    methyldiethanolammonium fluoride, tetramethylammonium fluoride,    triethylamine trihydrofluoride, hydrogen fluoride, fluoroboric acid,    tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic    acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic    acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate    and mixtures thereof; preferably the or at least one etchant    comprising fluoride is ammonium fluoride,    -   preferably in a total amount in the range of from 0.001 to 1        wt.-%, more preferably in the range of from 0.01 to 0.1 wt.-%,        based on the total weight of the cleaning composition;-   (B) one or more alkanolamines selected from the group consisting of    monoisopropanolamine, diisopropanolamine, triisopropanolamine,    2-(2-aminoethylamino)ethanol, 2-(2-aminoethoxy)-ethanol,    2-aminoethanol (CAS RN 141-43-5), 2-(N-methylamino) ethanol,    2-amino-1-propanol, 2-(2-hydroxyethylamino)ethanol (CAS RN    111-42-2), 2-[(2-aminoethyl)(2-hydroxyethyl)-amino]-ethanol,    tris-(2-hydroxyethyl)amine (CAS RN 102-71-6),    N-aminoethyl-N′-hydroxyethylethylenediamine,    N,N′-dihydroxyethyl-ethylenediamine,    2-[2-(2-aminoethoxy)ethylamino]ethanol,    2-[2-(2-aminoethylamino)-ethoxy]-ethanol,    2-[2-(2-aminoethoxy)-ethoxy]-ethanol, tertiary-butyldiethanolamine,    3-amino-1-propanol, isobutanolamine, 2-(2-aminoethoxy)-propanol and    mixtures thereof; preferably the or at least one alkanolamine is    tris-(2-hydroxyethyl)-amine, preferably in a total amount in the    range of from 10 to 20 wt.-%, more preferably in the range of from    12 to 17 wt.-%, based on the total weight of the cleaning    composition;-   (C) the or at least one sulfonic acid is methane sulfonic acid,    -   preferably in a total amount in the range of from 0.01 to 10        wt.-%, more preferably of from 0.1 to 1 wt.-%, based on the        total weight of the cleaning composition;-   (D) the or at least one corrosion inhibitor is glycine, preferably    in a total amount in the range of from 0.001 to 10 wt.-%, more    preferably of from 0.01 to 1 wt.-%, based on the total weight of the    cleaning composition;-   (E) citric acid,    -   preferably in a total amount in the range of from 0.1 to 25        wt.-%, more preferably in the range of from 5 to 25 wt.-%, even        more preferably in the range of from 10 to 25 wt.-% and yet even        more preferably in the range of from 15 to 25 wt.-%, based on        the total weight of the cleaning composition, and-   (F) water,    preferably as balance to a total of 100 wt.-% of the cleaning    composition,    which preferably has a pH in the range of from 2.5 to 5.5, more    preferably in the range of from 3 to 5, still more preferably in the    range of from 3.5 to 4.5.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also particularly preferred, consisting of:

-   (A) ammonium fluoride, preferably in a total amount in the range of    from 0.001 to 1 wt. %, more preferably in the range of from 0.01 to    0.1 wt.-%, based on the total weight of the cleaning composition,-   (B) tris-(2-hydroxyethyl)-amine, preferably in a total amount in the    range of from 10 to 20 wt.-%, more preferably in the range of from    12 to 17 wt.-%, based on the total weight of the cleaning    composition,-   (C) methane sulfonic acid, preferably in a total amount of from 0.01    to 10 wt.-%, more preferably in the range of from 0.1 to 1 wt.-%,    based on the total weight of the cleaning composition,-   (D) glycine, preferably in a total amount in the range of from 0.001    to 10 wt.-%, more preferably in the range of from 0.01 to 1 wt.-%,    based on the total weight of the cleaning composition,-   (E) citric acid, preferably in a total amount in the range of from    0.1 to 25 wt.-%, more preferably in the range of from 5 to 25 wt.-%,    even more preferably in the range of from 10 to 25 wt.-% and yet    even more preferably in the range of from 15 to 25 wt. %, based on    the total weight of the cleaning composition, and-   (F) water, preferably as balance to a total of 100 wt.-% of the    cleaning composition in each case,    which preferably has a pH in the range of from 2.5 to 5.5, more    preferably in the range of from 3 to 5, still more preferably in the    range of from 3.5 to 4.5.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred for post-etch or post ashresidue removal of one or more residues selected from the groupcomprising or consisting of

-   -   organic compounds, preferably organic polymers, comprising or        not comprising fluorine,    -   metal(-organic) complexes and    -   metallic materials,        from a substrate, wherein a low k material and/or a copper        material are part of the substrate.

With regard to a cleaning composition according to the invention asdefined herein (or a cleaning composition according to the invention asdescribed above or below as being preferred), metal(-organic) complexesare preferably selected from the group consisting of fluorine complexesof Ti, oxygen complexes of Ti, fluorine complexes of Cu, oxygencomplexes of Cu and mixtures thereof; and metallic materials arepreferably selected from the group consisting of Ti, TiN, La, LaN, Al,AlCu and mixtures thereof. Metallic materials as defined herein for thepurposes of the present invention do not comprise copper metal. A coppermaterial as defined herein is preferably copper metal.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred which has a pH in the rangeof from 2.5 to 5.5, preferably in the range of from 3 to 5, morepreferably in the range of from 3.5 to 4.5.

A cleaning composition according to the invention as defined herein (ora cleaning composition according to the invention as described above orbelow as being preferred) is also preferred which has a copper etchingrate in the range of from 0.01 to 0.1 nm/min, preferably in the range offrom 0.02 to 0.05 nm/min, preferably at a temperature in the range offrom 20° C. to 60° C., more preferably in the range of from 30° C. to50° C., even more preferably in the range of from 35° C. to 45° C. andyet even more preferably in the range of from 35° C. to 42° C.

The present invention also pertains to the use of a cleaning compositionaccording to the invention as defined herein (or to the use of acleaning composition according to the invention as described above orbelow as being preferred)

-   -   for removing post-etch or post ash residue from the surface of a        semiconductor substrate comprising a low k material and/or        copper,        -   wherein the post-etch or post ash residue preferably            comprises one or more residues selected from the group            comprising or consisting of:            -   organic compounds, preferably organic polymers,                comprising or not comprising fluorine,            -   metal(-organic) complexes and            -   metallic materials,    -   and/or    -   for cleaning a semiconductor substrate comprising a low k        material and/or copper, preferably after a step of etching one        or more substrate layers,        -   wherein the one or more substrate layers (i.e. from layers            which have been etched before) are preferably selected from            the group consisting of photoresist layer, bottom            anti-reflective coating layer, etch mask layer, inter-layer            dielectric layer and low k material layer;    -   and/or    -   for removing residues and contaminants from the surface of a        semiconductor substrate comprising a low k material and/or        copper,        -   wherein the residues and contaminants are preferably            selected from the group comprising or consisting of:            -   organic compounds, preferably organic polymers,                comprising or not comprising fluorine            -   metal(-organic) complexes and            -   metallic materials.

Generally, all aspects of the present invention discussed herein in thecontext of the inventive cleaning composition apply mutatis mutandis tothe use of said cleaning composition according to the invention, asdefined here above and below. And vice versa, all aspects of the presentinvention discussed herein in the context of the use of said cleaningcomposition according to the invention apply mutatis mutandis to theinventive cleaning composition.

With regard to the use of a cleaning composition according to theinvention as defined above, the terms “photoresist layer”, “bottomanti-reflective coating”, “etch mask”, “inter-layer dielectric” and “lowk material” shall have the meanings as defined above.

A use of a cleaning composition according to the invention as definedherein (or of a cleaning composition according to the invention asdescribed above or below as being preferred) is also preferred whereinthe use is in a dual damascene process for manufacturing a semiconductordevice.

The present invention also pertains to a process for the manufacture ofa semiconductor device from a semiconductor substrate, the processcomprising a step of post-etch or post ash residue removal from asubstrate (preferably a semiconductor substrate) by contacting thesubstrate at least once with a cleaning composition according to theinvention as defined above (or a cleaning composition according to theinvention as described above as being preferred).

Generally, all aspects of the present invention discussed herein in thecontext of the inventive cleaning composition and the inventive use of acleaning composition apply mutatis mutandis to the process for themanufacture of a semiconductor device comprising a step of post-etch orpost ash residue removal from a substrate according to the presentinvention, as defined here above and below. And vice versa all aspectsof the process for the manufacture of a semiconductor device accordingto the present invention discussed herein apply mutatis mutandis to theinventive cleaning composition and the inventive use of a cleaningcomposition.

A process comprising a step of post-etch or post ash residue removalfrom a substrate according to the invention as defined herein (or aprocess according to the invention as defined herein as being preferred)is also preferred, wherein

-   -   the semiconductor substrate comprises a layer of copper and/or        an oxide of copper and/or a copper hydroxide compound and/or a        low k material, and/or    -   in the step of post-etch or post ash residue removal, the        residue comprises one or more residues selected from the group        comprising or consisting of:        -   organic compounds, preferably organic polymers, comprising            or not comprising fluorine,        -   metal(-organic) complexes and        -   metallic materials.

A copper hydroxide compound (also referred to as Cu(OH)_(x)) which canbe present in this preferred variant of the process according to theinvention preferably comprises or consists of Cu(OH)₂.

It is a particular achievement of the process comprising a step ofpost-etch or post ash residue removal from a substrate according to theinvention that it allows excellent pos-tetch or post ash residue removalwhere the post-etch or post ash residues are of various origins (e.g.residues and contaminants from the previous etching of one or morelayers on the semiconductor substrate selected from the group consistingof photoresist layer, bottom anti-reflective coating layer, etch masklayer, inter-layer dielectric layer and low k material layer, see above)while at the same time preserving fully or to a very high extent, layersof metallic interconnect material, in particular of copper, and of low kmaterial and/or while particularly effectively removing copper oxidecompounds (also referred to as CuO_(x) compounds) and/or copperhydroxide compounds from the substrate.

A process comprising a step of post-etch or post ash residue removalfrom a substrate according to the invention as defined herein (or aprocess according to the invention as defined above as being preferred)is particularly preferred, wherein the process comprises at least onestep of etching one or more substrate layers, preferably comprising astep of wet etching or dry etching, wherein:

-   -   the step of post-etch or post ash residue removal is performed        after said at least one step of etching one or more substrate        layers,        and/or (preferably “and”)    -   the step of post-etch or post ash residue removal from a        substrate comprises the removal of one or more oxides or        hydroxides of copper and/or the removal of organic compounds,        preferably organic polymers, comprising or not comprising        fluorine.

In the above-defined preferred process, dry etching is preferred andpreferably comprises reactive ion etching and plasma etching. Where morethan one step of etching one or more substrate layers is carried out inthe above-defined preferred process, the or a step of post-etch or postash residue removal is preferably performed after each of said more thanone steps. In the above defined preferred process, hydroxides of copperpreferably comprise or consist of Cu(OH)₂.

A process comprising a step of post-etch or post ash residue removalfrom a substrate according to the invention as defined herein (or aprocess according to the invention as defined herein as being preferred)is also preferred, which is performed at a temperature in the range offrom 20° C. to 60° C., more preferably in the range of from 30° C. to50° C., even more preferably in the range of from 35° C. to 45° C. andyet even more preferably in the range of from 35° C. to 42° C.

In many cases, a process comprising a step of post-etch or post ashresidue removal from a substrate according to the invention as definedherein (or a process according to the invention as defined above asbeing preferred) is also preferred, wherein the one or more substratelayers are selected from the group consisting of photoresist layer;bottom anti-reflective coating layer; etch mask layer, preferablypolymer etch mask layer; inter-layer dielectric layer, preferablysilicon oxynitride layer and low k material layer, preferably poroussilicon dioxide layer and porous carbon-doped silicon dioxide layer.

FIGURES

FIG. 1: FIG. 1 shows a scanning electron microscope photography (lengthof picture equivalent to about 880 nm) of a nanometer-scale structure onthe surface of a semiconductor wafer after a step of etching and beforeperforming a step of post-etch or post ash residue removal (rinsing)from the surface (at 10 kV: accelerating voltage of the electrons), 5.8mm (working distance to the substrate)×150 k SE(U)) magnificationfactor).

FIG. 2: FIG. 2 shows a scanning electron microscope photography (lengthof picture equivalent to about 750 nm) of the nanometer-scale structureon the surface of a semiconductor wafer shown in FIG. 1, but afterperforming a step of post-etch or post ash residue removal (rinsing)with a composition 11 (see examples 1 and 2) according to the invention(at 10 kV, 5.8 mm×150 k SE(U)). It can be seen in FIG. 2 that theglobular-shaped residues in the depressions on the surface (holes)previously present (see FIG. 1) have been removed, without causing anyvisible damage to any other part of the surface, as a result of theexposure of the surface of the semiconductor wafer to the composition ofthe invention.

FIG. 3: FIG. 3 shows a scanning electron microscope photography (lengthof picture equivalent to about 880 nm) of another nanometer-scalestructure on the surface of a semiconductor wafer after a step ofetching and before performing a step of post-etch or post ash residueremoval (rinsing) from the surface (at 10 kV, 5.8 mm×150 k SE(U)).

FIG. 4 FIG. 4 shows a scanning electron microscope photography (lengthof picture equivalent to about 750 nm) of the nanometer-scale structureon the surface of a semiconductor wafer shown in FIG. 3, but afterperforming a step of post-etch or post ash residue removal (rinsing)with a composition 11 (see examples 1 and 2) according to the invention(at 10 kV, 5.8 mm×150 k SE(U)). It can be seen on the picture that theglobular-shaped residues in the depressions on the surface (holes)previously present (see FIG. 3) have been completely removed, withoutcausing any visible damage to any other part of the surface, as a resultof the exposure of the surface of the semiconductor wafer to thecomposition of the invention.

EXAMPLES

The following examples are meant to further explain and describe theinvention without limiting its scope.

Example 1: Preparation of Composition According to the Invention

The following composition according to the invention was prepared bymixing the components (A) to (F) as shown in table 1 below.

TABLE 1 Composition according to the invention Component ConstituentComposition [wt.-%] (A) Ammonium fluoride 0.01 to 0.1  (B)Tris-(2-hydroxyethyl)-amine 12 to 17 (C) Methane sulfonic acid 0.1 to 1 (D) Glycine 0.01 to 1   (E) Citric Acid 15 to 25 (F) Water (electronicgrade)  55.9 to 72.88 pH 3.5 to 4.5

Example 2: Measurement of Copper Etch Rate

The etch rate of the composition of the invention from Example 1(referred to as “test composition 11” hereinafter) was determinedaccording or analogous to methods described in document WO 2015/173730:

Blanket Si test wafers (with consecutive layers of copper, a low kmaterial and TiN) were selected from appropriate commercial sources andbroken into smaller coupons. Then, the initial film or layer thicknessof the applicable material was measured (for copper, a 4-point probe wasused). The test composition 11 was brought to a temperature in the rangeof from 35° C. to 45° C. and stirred mechanically. The coupons werefixed to a mechanical holder and, after pre-treatment with oxalic acid,were contacted with the test composition 11 for about 10 minutes in abeaker. Subsequently, the coupons were withdrawn from the testcomposition and cleaned with ultra-pure water for a period of about 1minute. Afterwards, the coupons were dried with nitrogen gas. Theresidual thickness of the copper layer was measured again as describedabove (4-point probe for copper) and the etch rate was calculated asusual:

For example, when the initial thickness of the copper layer on theblanket test wafer was 33 nm and the thickness of the copper layer onthe blanket test wafer after contact with the test composition (seeabove) was 30 nm, and the reaction time (i.e. contact time of the wafercoupon with the test composition) was 10 min, the copper etch rate wascalculated as follows:

Copper Etch Rate (hypothetical)=(33−30)/10·nm/min=0.3 nm/min

In a similar experiment, a known cleaning composition for a substrateused in semiconductor industry from the prior art (referred to as“comparative composition C1” hereinafter) was tested which was asolvent-based composition and showed a pH of 8.0.

The results from this test are shown in table 2 below:

TABLE 2 Results from etch rate test Test Comparative CompositionComposition Parameter I1 C1 Copper etch rate [nm/min] 0.02-0.03 0.2-0.3Operating temperature [° C.] 35-42 40 Smile curve defect observed No YesQueue time >20 hours <5 hours

From this test result it can be seen that the cleaning composition ofthe present invention has a particularly low copper etch rate and istherefore particularly well suited as cleaning composition for asemiconductor substrate which comprises copper, e.g. a layer of copper.

Example 3: Compatibility of Compositions with Several Materials

The compatibility of the compositions according to the invention withtypical materials used in the manufacture of semiconductor substrateswas tested by measuring etch rates of test composition 11 (see examples1 and 2) for several substrates in a manner known in the art.

As a result of this test, it was found that test composition 11 showedetch rates of below 0.1 nm/min (equivalent to below 1 Å/min) for thefollowing materials: Tetraethylorthosilicate; fluorinatedtetraethylorthosilicate; hafnium oxide; titanium; titanium nitride andtungsten.

Example 4: Yield Increase of Functioning Chips on a Wafer

A step of post-etch and/or post ash residue removal was performed on aseries of semiconductor wafers (comprising in each case a layer ofcopper, an oxide of copper, a copper hydroxide compound and a low kmaterial) in a production environment by exposing the freshly etchedpatterned surfaces of a first series (“series A”) of such semiconductorwafers to composition 11 (see examples 1 and 2) according to theinvention, at 45° C. for 60 s (i.e. exposing the surfaces to saidcomposition) and by exposing the freshly etched patterned surfaces of asecond series (“series B”) of such semiconductor wafers to a comparativecomposition C1 not according to the invention (see example 3 above), inan equal manner as was done with the semiconductor wafers of series A.

After full processing of the semiconductor wafers of series A and B (thefull processing comprising in each case the step of post-etch and/orpost ash residue removal as explained above), the yield of functioningtransistors or transistor clusters on the finished wafers was measuredfor both series of semiconductor wafers in a manner known per se.

As a result, it was found that the yield (i.e. the number of functioningtransistors or transistor clusters in a series of semiconductor wafersin relation to all transistors or transistor clusters from that series)of the series A of semiconductor wafers which were treated withcomposition 11 according to the invention was higher than the respectiveyield of the series B of semiconductor wafers which were treated withcomparative composition C1 not according to the invention:

Starting from the yield of functioning transistors or transistorclusters on semiconductor wafers received after exposure of the freshlyetched patterned surfaces on semiconductor wafers of series B tocomparative composition C1 and taking this yield as “100% yield”, theyield of functioning transistors or transistor clusters on semiconductorwafers received after exposure of the freshly etched patterned surfaceson semiconductor wafers of series A to inventive composition 11 was101.9% when compared to the respective yield of series B.

1. A cleaning composition, comprising: (A) one or more etchantscomprising fluoride; (B) one or more alkanolamines selected from thegroup consisting of monoisopropanolamine, diisopropanolamine,triisopropanolamine, 2-(2-aminoethylamino)-ethanol,2-(2-aminoethoxy)-ethanol, 2-aminoethanol, 2-(N-methylamino) ethanol,2-amino-1-propanol, 2-(2-hydroxyethylamino)ethanol,2-[(2-aminoethyl)(2-hydroxyethyl)-amino]-ethanol,tris-(2-hydroxyethyl)-amine,N-aminoethyl-N′-hydroxyethylethylenediamine,N,N′-dihydroxyethyl-ethylenediamine,2-[2-(2-aminoethoxy)-ethylamino]ethanol,2-[2-(2-aminoethylamino)ethoxy]-ethanol,2-[2-(2-aminoethoxy)-ethoxy]-ethanol, tertiary-butyldiethanolamine,3-amino-1-propanol, isobutanolamine, 2-(2-aminoethoxy)-propanol andmixtures thereof, (C) one or more sulfonic acids selected from the groupconsisting of methane sulfonic acid, ethanesulfonic acid,propanesulfonic acid, butanesulfonic acid, hexanesulfonic acid,3-(N-morpholino)propane sulfonic acid, 2-(N-morpholino)ethanesulfonicacid, N-cyclohexyl-2-aminoethanesulfonic acid,3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid,N-cyclohexyl-3-aminopropanesulfonic acid and mixtures thereof, (D) oneor more corrosion inhibitors selected from the group consisting ofbenzotriazole, 5-methyl-benzotriazole, 1,2,4-triazole, 5-aminotetrazole,1-hydroxybenzotriazole, 5-amino-1,3,4-thiadiazol-2-thiol,3-amino-1H-1,2,4 triazole, 3,5-diamino-1,2,4-triazole, tolyltriazole,5-phenyl-benzotriazole, 5-nitro-benzotriazole,3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,2-(5-amino-pentyl)-benzotriazole, 1-amino-1,2,3-triazole,1-amino-5-methyl-1,2,3-triazole, 3-mercapto-1,2,4-triazole,3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole,halobenzotriazoles where halo is selected from the group consisting offluorine, chlorine, bromine and iodine, naphthotriazole,1H-tetrazole-5-acetic acid, 2-mercaptobenzothiazole,1-phenyl-2-tetrazoline-5-thione, 2-mercaptobenzimidazole,4-methyl-2-phenylimidazole, 2-mercaptothiazoline,2,4-diamino-6-methyl-1,3,5-triazine, thiazole, imidazole, benzimidazole,triazine, methyltetrazole, 1,3-dimethyl-2-imidazolidinone,1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,2H-imidazole-2-thione, 4-methyl-4H-1,2,4-triazole-3-thiol,5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate,indazole, adenine, cytosine, guanine, thymine, 2,2′-azanediyldiaceticacid, propanethiol, ascorbic acid, thiourea, ethylene urea, ethylenethiourea, 1,1,3,3-tetramethylurea, urea, uric acid, glycine,dodecylphosphonic acid, oxalic acid, malonic acid, succinic acid,nitrilotriacetic acid and mixtures thereof; (E) citric acid, and (F)water.
 2. The cleaning composition of claim 1, wherein the one or moreetchants comprising fluoride (A) are selected from the group consistingof ammonium fluoride, ammonium bifluoride, triethanolammonium fluoride,diglycolammonium fluoride, methyldiethanolammonium fluoride,tetramethylammonium fluoride, triethylamine trihydrofluoride, hydrogenfluoride, fluoroboric acid, tetrafluoroboric acid, ammoniumtetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate,trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate,tetrabutylammonium tetrafluoroborate and mixtures thereof, and/or atotal amount of the one or more etchants comprising fluoride (A) is in arange of from 0.001 to 1 wt.-%, based on a total weight of the cleaningcomposition.
 3. The cleaning composition of claim 1, wherein the one ormore alkanolamines (B) is tris-(2-hydroxyethyl)-amine and/or a totalamount of the one or more alkanolamines (B) is in a range of from 10 to20 wt.-%, based on a total weight of the cleaning composition.
 4. Thecleaning composition of claim 1, wherein the one or more sulfonic acids(C) is methane sulfonic acid and/or a total amount of the one or moresulfonic acids (C) is in a range of from 0.01 to 10 wt.-%, based on atotal weight of the cleaning composition.
 5. The cleaning composition ofclaim 1, wherein the one or more corrosion inhibitors (D) is glycineand/or a total amount of the one or more corrosion inhibitors (D) is ina range of from 0.001 to 10 wt.-%, based on a total weight of thecleaning composition.
 6. The cleaning composition of claim 1, wherein atotal amount of citric acid (E) is in a range of from 0.1 to 25 wt.-%,based on a total weight of the cleaning composition.
 7. The cleaningcomposition of claim 1, comprising: (A) one or more etchants comprisingfluoride, wherein a total amount of the one or more etchants comprisingfluoride is (A) in a range of from 0.001 to 1 wt.-%, based on a totalweight of the cleaning composition; (B) one or more alkanolaminesselected from the group consisting of monoisopropanolamine,diisopropanolamine, triisopropanolamine, 2-(2-aminoethylamino)-ethanol,2-(2-aminoethoxy)-ethanol, 2-aminoethanol, 2-(N-methylamino) ethanol,2-amino-1-propanol, 2-(2-hydroxyethylamino)ethanol,2-[(2-aminoethyl)(2-hydroxyethyl)-amino]-ethanol,tris-(2-hydroxyethyl)-amine,N-aminoethyl-N′-hydroxyethylethylenediamine,N,N′-dihydroxyethyl-ethylenediamine,2-[2-(2-aminoethoxy)-ethylamino]ethanol,2-[2-(2-aminoethylamino)ethoxy]-ethanol,2-[2-(2-aminoethoxy)-ethoxy]-ethanol, tertiary-butyldiethanolamine,3-amino-1-propanol, isobutanolamine, 2-(2-aminoethoxy)-propanol andmixtures thereof; (C) one or more sulfonic acids selected from the groupconsisting of methane sulfonic acid, ethanesulfonic acid,propanesulfonic acid, butanesulfonic acid, hexanesulfonic acid,3-(N-morpholino)propane sulfonic acid, 2-(N-morpholino)ethanesulfonicacid, N-cyclohexyl-2-aminoethanesulfonic acid,3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid,N-cyclohexyl-3-aminopropanesulfonic acid and mixtures thereof, wherein atotal amount of the one or more sulfonic acids (C) is in a range of from0.01 to 10 wt.-%, based on the total weight of the cleaning composition;(D) one or more corrosion inhibitors selected from the group consistingof benzotriazole, 5-methyl-benzotriazole, 1,2,4-triazole,5-aminotetrazole, 1-hydroxybenzotriazole,5-amino-1,3,4-thiadiazol-2-thiol, 3-amino-1H-1,2,4 triazole,3,5-diamino-1,2,4-triazole, tolyltriazole, 5-phenyl-benzotriazole,5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole,1-amino-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole,1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole,5-phenylthiol-benzotriazole, halobenzotriazoles where halo is selectedfrom the group consisting of fluorine, chlorine, bromine and iodine,naphthotriazole, 1H-tetrazole-5-acetic acid, 2-mercaptobenzothiazole,1-phenyl-2-tetrazoline-5-thione, 2-mercaptobenzimidazole,4-methyl-2-phenylimidazole, 2-mercaptothiazoline,2,4-diamino-6-methyl-1,3,5-triazine, thiazole, imidazole, benzimidazole,triazine, methyltetrazole, 1,3-dimethyl-2-imidazolidinone,1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,2H-imidazole-2-thione, 4-methyl-4H-1,2,4-triazole-3-thiol,5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate,indazole, adenine, cytosine, guanine, thymine, 2,2′-azanediyldiaceticacid, propanethiol, ascorbic acid, thiourea, ethylene urea, ethylenethiourea, 1,1,3,3-tetramethylurea, urea, uric acid, glycine,dodecylphosphonic acid, oxalic acid, malonic acid, succinic acid,nitrilotriacetic acid and mixtures thereof; (E) citric acid, wherein atotal amount of the citric acid (E) is in a range of from 0.1 to 25wt.-%, based on the total weight of the cleaning composition and (F)water.
 8. The cleaning composition of claim 1, consisting of: (A)ammonium fluoride, (B) tris-(2-hydroxyethyl)-amine, (C) methane sulfonicacid, (D) glycine, (E) citric acid, and (F) water. 9-10. (canceled) 11.A process of manufacturing a semiconductor device from a semiconductorsubstrate, the process comprising removing post-etch or post ash residuefrom a substrate by contacting the substrate at least once with thecleaning composition of claim
 1. 12. The process of claim 11, whereinthe semiconductor substrate comprises a layer of copper and/or an oxideof copper and/or a copper hydroxide compound and/or a low k material,and/or in the removing, the post-etch or post ash residue comprises oneor more residues selected from the group consisting of: organiccompounds, metal(-organic) complexes and metallic materials.
 13. Theprocess of claim 11, comprising etching one or more substrate layers,etching wherein the removing is performed after the etching, and/or theremoving comprises the removal of one or more oxides or hydroxides ofcopper and/or the removal of organic compounds.
 14. A process ofremoving post-etch or post ash residue from a substrate comprising a lowk material and/or a copper material, the process comprising contactingthe post-etch or post ash residue with the cleaning composition of claim1, wherein the post-etch or post ash residue comprises one or moreresidues selected from the group consisting of: organic compounds,metal(-organic) complexes and metallic materials.
 15. A process ofremoving post-etch or post ash residue from a surface of a semiconductorsubstrate comprising a low k material and/or copper, the processcomprising contacting the post-etch or post ash residue with thecleaning composition of claim 1, optionally wherein the post-etch orpost ash residue comprises one or more residues selected from the groupconsisting of: organic compounds, metal(-organic) complexes and metallicmaterials.
 16. The process of claim 15, wherein the post-etch or postash residue comprises one or more residues selected from the groupconsisting of: organic compounds, metal(-organic) complexes and metallicmaterials.
 17. A process of cleaning a semiconductor substratecomprising a low k material and/or copper, the process comprisingcontacting the semiconductor substrate with the cleaning composition ofclaim 1, optionally after etching one or more substrate layers, whereinthe one or more substrate layers are optionally selected from the groupconsisting of a photoresist layer, a bottom anti-reflective coatinglayer, an etch mask layer, an inter-layer dielectric layer and a low kmaterial layer.
 18. A process of removing residues and contaminants froma surface of a semiconductor substrate comprising a low k materialand/or copper, the process comprising contacting the semiconductorsubstrate with the cleaning composition of claim 1, optionally whereinthe residues and contaminants are selected from the group consisting of:organic compounds, optionally comprising fluorine metal(-organic)complexes and metallic materials.